The present inventors invented an apparatus where a hemimorphic crystal, such as a lithium niobate (LiNbO3) single crystal, is contained within a housing having low gas pressure, and the temperature of this crystal is periodically changed so that electrons which are generated on the surface of the crystal because they cannot follow the offset of the charge on the surface collide with an X-ray target or the hemimorphic crystal using a high electrical field generated by the crystal, and thus, X-rays are generated (Japanese Laid-Open Patent Publication No. 2005-174556), and furthermore, invented an apparatus where a pair or pairs of such hemimorphic crystals are placed so as to face each other, so that an X-ray target is efficiently irradiated with electrons generated on the surface of the crystals while the electrons multiply, and thus, more intense X-rays are generated (Japanese Laid-Open Patent Publication No. 2005-285575).
In terms of the intensity of the X-rays generated according to the invention, the larger the amount of electrons separated from the crystal when the temperature of the hemimorphic crystal is changed and released into the housing is, the more intense the gained X-rays are, but there is a restriction, such that the temperature for heating the hemimorphic crystal must be the Curie point or lower, and thus, the range in terms of the change in the temperature of the crystal is limited, and therefore, it is difficult to greatly increase the amount of electrons and charged particles separated from the crystal. That is to say, in terms of the technical background, it can be said that the intensity of the generated X-rays is limited, to a certain degree, by the size of the crystal and the temperature range for heating and cooling.
The present inventors focused on the electron acceleration function resulting from the high electrical field generated by a hemimorphic crystal, and conducted a research in order to overcome the problem of the amount of electrons separated and released from the crystal being limited, and as a result, proposed an idea: that a greater number of electrons be made to accelerate so as to collide with an X-ray target using the high electrical field by providing an apparatus for positively supplying electrons, that is to say, an electron generator (electron supplier), in the vicinity of the crystal so that more intense, continuous X-rays and characteristic X-rays can be gained in accordance with the purpose, by appropriately controlling the density of electron radiation using this electron generator.
(Patent Document 1) Japanese Laid-Open Patent Publication No. 2005-174556
(Patent Document 2) Japanese Laid-Open Patent Publication No. 2005-285575